


Robot Siblings

by keiyakins



Category: Undertale (Video Game)
Genre: Agender Chara (Undertale), Blunt Mentions of Child Murder, By the Murdered Children, Chara & Frisk (Undertale) Share a Body, Frisk (Undertale) Uses Sign Language, Gen, Ghost Chara (Undertale), Humorous Mentions of Bathroom Usage, Mild Language, Nonbinary Chara (Undertale), Nonbinary Frisk (Undertale), Selectively Mute Frisk (Undertale), The Gender Binary Has No Power Here, it's sorta complicated
Language: English
Status: In-Progress
Published: 2020-07-10
Updated: 2020-07-10
Packaged: 2021-03-05 03:35:04
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,904
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25177771
Author URL: https://archiveofourown.org/users/keiyakins/pseuds/keiyakins
Summary: Alphys and Frisk have been busy ever since the Barrier fell building on the magitek behind Mettaton, and they're finally ready to try bringing one of the Six Dead Kids back.Oh, and Chara's sulking and being asocial, but what else is new?
Relationships: Minor or Background Relationship(s)
Comments: 2
Kudos: 15





	Robot Siblings

"Are you s-sure you don't want me or Undyne in the room?" Alphys shuffled nervously. "In case things… g-go wrong?"

Frisk smiled and shook their head. [His last memory is being killed by a monster,] they signed, saving their voice for when Elliot woke up. [Even Toriel will be standing behind the curtain, and he knows her personally.]

"Frisk knows what they're doing, Alphy." Undyne put a hand on the smaller monster's shoulder. "They survived the Underground before I trained 'em for the last couple years. I'd like to see someone try to hurt them now!"

Frisk was pretty sure it was impossible for Undyne's speeches to fail to fire someone up.

"Indeed. And in the unlikely case that Ellie does manage to harm Frisk, I will be right here, and you in the next room." Toriel sighed. "I cannot say I like Frisk putting themself in danger, but their arguments for why the first face he sees should be a human are sound."

"I know." Alphys said quietly. "Call if you need us." Undyne gently guided her into the next room.

Frisk turned back to the unmoving robot body and smiled. It was time to meet one of their siblings for the first time.

They flipped the switch on the service panel. The machinery whirred to life as it carefully pulled the cyan soul from the can in which Asgore had trapped it and inserted into the robotic shell.

The pause as the soul and body synchronized was just long enough for Frisk to fear it had failed before he jerked to life, screaming. Frisk winced. They should have expected that, they knew better than anyone how painful it was to be killed.

"Shh, shh, you're safe now!" Frisk's voice was shaky and rough from disuse, but combined with the gentle touch, Elliot was calm enough to actually see them soon enough.

"Who are you? Where am I?" Elliot choked out, his voice still full of fear.

"My name is Frisk," they replied, carefully leaving off the 'Dreemurr' for the moment, "And you're in a laboratory back on the surface."

"Back on the surface?" Elliot's fear was being replaced with confusion. Confusion can be remedied with information.

"Yes. What happened after you Fell into the Underground was real. All of it. Even the part where Asgore…" Frisk choked on the words. "You know."

Elliot nodded. "So how am I here now?"

Frisk shook their head and motioned towards a curtain at the back of the room. Toriel stepped out from behind it.

"Ellie, child… is it okay if I come sit with you? Frisk has a hard time talking, and they have done very well. I can translate their sign language for you for the rest of the explanations."

Elliot's eyes widened at the sight of her. "Toriel!" He tried to run to her for a hug, but was held back by cabling and the soul conduit. "Wha-?" He reached behind him, trying to figure out what was holding him back.

Toriel took that as permission to approach and came over, sitting as close as she could so Elliot could at least touch her. Frisk began to sign, and Toriel translated.

[You're here because we - and some others you can meet later - worked very hard to build a robot body that can house your soul. I know it's not enough to make up for being killed in the first place, but it's the best way to bring you back we could come up with.]

Elliot looks pensive. "You said 'we'. Are you with Asgore somehow?"

Frisk shifted uncomfortably. [He's my adoptive father. I promise you never have to meet with him if you want - we can find a way to get you into the human foster system, or a monster family somewhere, or we can just keep him away from mom's, I mean Toriel's place. It's up to you.]

Elliot shook his head. "I don't want to see him right now, but if I stay with you and Toriel I can't keep him away forever. … I can stay with you, right Toriel? You were so nice to me in the Ruins, but then I had to go and mess it all up…" he looks on the verge of tears. Between Alphys's brains, Mettaton's help, and integrating work done by humans on faces, his head was almost totally lifelike.

"Of course, my child!" Toriel hugged him, awkwardly avoiding the various cables. "We already have a room for you, if you will forgive my failure." Toriel was just shy of tears too.

Frisk smiled and waited for them to finish hugging it out and return to looking at them before continuing. [You'll need to stay here tonight while Alphys finishes the last checks. Toriel or I can stay with you as long as you want. Is it okay if I invite her in? She's a monster, but I promise she won't hurt you. There's no war anymore.]

"Yeah… okay."

* * *

Elliot was soon disconnected and walking around the lab. He was delighted to learn that Toriel had brought a few outfits for him and promised to take him shopping for more when he felt up to it, and even more delighted when he realized there was a dress and a couple cute ribbons in there. "I'm definitely a boy," he asserted to Frisk when they asked about it using a text to speech app on their phone. "I just like being cute sometimes."

Frisk decided that was the time to return Elliot's Faded Ribbon and Toy Knife.

Elliot hugged Frisk after that. "Thank you so much. Alphys told me how much work you'd put into bringing me back, and how worried you were that I'd resent you. I don't. I'm more surprised you don't resent me coming in and taking some of mom's love away."

Frisk hugged him for a bit before pulling away to type something on their phone. When they were done, their phone spoke for them. «That's not how love works. I don't love Toriel any less because I also love the rest of my family. And the same goes for you. We've only just met, but if you'll take me as your sibling, you're my brother now. And that means I love you too.»

"You promise?"

«I promise.»

"Then I'd love to be your brother." His tears were getting Frisk's shirt damp, but they didn't mind in the slightest. "... Will you teach me to understand the hand talking thing you did earlier, too?"

Frisk grinned, stepping back for a moment as they raised a loose fist to their shoulder before turning it up and down. «That means yes.» they typed, getting a small laugh for their trouble.

* * *

Moving into Toriel's didn't take too long, since Elliot only really had one bag.

"You may choose any of the empty rooms upstairs," Toriel said with her soft smile. "Frisk, can you show him around and make sure he settles in? I am going to bake a welcome pie."

Frisk nodded and motioned to Elliot to follow.

"So uh… why are there so many rooms anyway? I feel like I know the answer but I don't know how I could know specifically that there are five others who… Fell... between us." Elliot's face was unreadable.

Frisk looked down at their toes. They'd talked to Toriel and agreed to not bring this up just yet, but if Elliot did to be honest. «There were. We're going to save them too. As for how you know that...»

Frisk sighed and sat down on the bed of the room Elliot was considering. The furnishing was sparse, just the essential bed and closet really, but they'd already discussed plans to go shopping tomorrow, and that included a trip to the furniture store. They offered a seat beside them as they typed.

«Disembodied souls shouldn't be able to form memories. That much is well understood by monster animology - the science of the soul. There's just no mechanism for it. The problem is… sometimes they do anyway. Vague, dreamlike memories, but memories. In your case, you're probably remembering when the barrier was broken.»

Frisk went on to explain everything. Chara and Asriel. Asgore's greatest mistake. How Alphys accidentally created Flowey. How the lack of a soul drove Flowey to destruction as the only way to feel. How he became the Absolute God of Hyperdeath. And how Frisk had been forced to leave him behind.

They didn't realize they were crying until Elliot put an arm around them. "It's okay. You can cry if you need to. I'll be here as long as you need." This little boy - he'd Fallen just before his sixth birthday and stayed with Toriel for a bit over a year before outgrowing the ruins - was able to just sit and hold his sibling until they felt better. That only made Frisk cry more, knowing how their time Underground, and whatever drove them up the mountain in the first place, had forced both of them to grow up faster than any kid should. The other five too, most likely. 

They let out their tears and hugged their brother back. "Thank you, Elliot." Frisk managed to squeeze out.

"You're my sib, I couldn't just leave you crying." Elliot stated matter of factly. "Also um, you're family now, so can call me Ellie or Ell if you want." He smiled at Frisk. "Now come on, I wanna check that corner room before I decide!"

* * *

Frisk flopped onto their bed exhausted, but they couldn't sleep just yet.

"So the first one went well. That doesn't mean anything, you know." said a voice only Frisk could hear. They sighed and pulled themself up to look at the ghostly figure across the room.

[Hi Chara.] they signed. [Thank you for being quiet the last couple days.]

"Meh. You know I'm not a fan of the sappy stuff." Their red eyes looked right through Frisk's body, seeming to focus on their soul. If they did that in life, it would definitely explain where the idea of Chara being a demon came from.

[Yeah, but don't you want to meet our brother?] Frisk was always pushing Chara to be more social. Chara, meanwhile, insisted that they were dead and shouldn't talk to anyone but Frisk. It was one of their regular arguments.

"Elliot isn't my brother." Chara explained with an exasperated sigh. "I put up with you calling yourself my sibling because we're stuck together like this, but I never even called Asriel my brother, and I loved him more than anything else in the world." Their eyes narrowed at Frisk. As far as either of them knew, ghost Chara couldn't cry, but their connection let Frisk feel their sorrow as their own.

[I'm sorry…] Frisk began, but Chara cut them off. 

"Forget it. I know you're prone to loving everyone. Good night, Frisk." Chara waved their hand through a magitek sensor Frisk had built out of parts Aunt Alphys let them tinker with and the lights started to fade out.

[Good night, Chara.]

* * *

The next day, Toriel, Elliot, and Frisk and Chara met up with Undyne and Mettaton at the mall. Between the two of them, they could cover just about any fashion style, and Frisk's wardrobe had a lot of their influence to cover whatever they felt like on a given day. Today they were wearing their hair in a low ponytail, with a simple striped tunic, leggings, and boots, as well as Chara’s locket under their clothes. Undyne had helped pick the boots, which meant they were just as comfortable as they were fashionable.

"Oh, there you are, darlings!" Mettaton's voice cut through the crowd as easily as it would an empty room, drawing Frisk back to the present with a smile. "Over here!"

There were advantages to having an eight foot tall goat monster for a mom, and being able to easily follow in her wake to get through a crowd was one of the less obvious. Frisk gave a polite smile and wave to a few people who stared while Toriel introduced Mettaton and Elliot - they might not be on the clock, but they were still the Ambassador for Monsterkind to Humanity. And a member of the royal family. And, technically, the heir to the monarchy of the Kingdom of Monsters, though they doubted it'd ever come to them having to take the crown.

At the moment though, they were going to focus on being a friendly, outgoing kid and helping their brother get settled in. Even if they could feel Chara rolling their eyes at their sap.

"So where to first, lil' punk?" Undyne asked with her usual enthusiasm. "Wanna start at the practical end and save the cool stuff for last, or attack the best stuff first and then breeze through the rest?"

"Oh, um… I don't know…" Elliot tugged at his t-shirt. When he'd heard they were going to a predominantly human mall, he'd insisted on dressing entirely masculine. "I guess we should start with the practical stuff? Pants and shirts and shorts and socks and underwear."

"Sounds like a plan to me, darling! We'll save the best for last! Onwards!" Mettaton practically danced his way across the mall. "I know all the best places for kids your size! Masculine or feminine first?"

Elliot froze. "I… I'm a boy," he whispered. "I know I can dress how I like around monsters but there's too many humans here…"

Mettaton stopped on a dime and twirled around to face him. "Nonsense, darling! You can wear whatever you like! I do. Frisk does. Why not you?"

"T...that's different!" Elliot protested. "You're a monster robot and Frisk is Frisk, not a boy or a girl!"

Undyne crouched down. "A'ight, lil' punk. I'm gonna lay this out. One, who cares what idiots think. And two," she stood up to her full height and bellowed "IF ANYONE TRIES TO GIVE YOU SHIT FOR IT I'LL ESCORT THEM OUT THROUGH THE SKYLIGHTS!"

"Language, Undyne." Toriel tapped her foot on the ground and glared.

"Er, right, sorry."

Elliot watched the whole exchange with a bewildered look on his face… then suddenly started laughing. "I'm still scared," he admitted, "but you're right. Let's do this."

* * *

By the time they were done, Elliot had chosen a mix of colorful and sturdy clothes he could wear for any occasion. Fortunately for Frisk’s job as ambassador, Undyne hadn’t had to make good on her promise. No one was brave enough to say anything under the combined glares of Undyne and Toriel.

"So what’s for lunch?" Undyne asked with a stretch as she loaded the last of the bags she was carrying. "Or are we gonna split now? Alphys and I can scrounge something up for Frisk at home before I gotta go teach."

"What do you teach?" Elliot asked curiously. He was wearing one of his new skirts over his shorts, and seemed much less scared than he had earlier… though he was still sticking close to Toriel.

"Mixed species self-defense." Undyne grinned. "Frisk helps sometimes ‘cause I know they can take being my demonstration buddy, but today they’re spending the afternoon with Alphys doing nerd stuff."

Frisk nodded as they typed. «I stay pretty busy, even during school breaks. Mom keeps worrying I’ll burn myself out, but I make sure to schedule rest days.»

"I just worry about your health, my child…" Toriel started before shaking her head. "But now is not the time for that old argument. I propose Elliot choose where we go for lunch."

"Is there a good pizza place nearby?" he asked, grinning. "I haven’t had a good pizza since before I, uh. Met mom." His grin faded.

"YEAH there is!" Undyne immediately exclaimed. "There’s this place over on the corner of River Inside Curve and Underground Access that has the best pizza. And you can order it prepped monster or human, too!"

"That sounds good then." Elliot said a bit quietly.

Frisk put a friendly hand on his shoulder and smiled before climbing into the back seat of Toriel's van and patting the seat beside them. Elliot followed.

On the way there, Frisk pulled out their phone again and started typing. «We didn’t mention this until now, but you should probably know now that it’s best for you to eat monster food.»

"Why is that? I’m human. Sort of." Elliot was mostly trying to pretend he was still fully human.

«Your soul is 100% human.» Frisk agreed, «But your new body runs differently. You don’t need all the vitamins and minerals humans do, and recharging from monster food is far more efficient than the simple chemical extraction we were able to cram in.» Frisk donned an embarrassed smile. «Honestly, it’s mostly there so you can, uh, get rid of the byproducts of eating human.»

"Ew!" Elliot laughed.

«Yeah. If it’s any comfort, I’ve been eating mostly monster food for years now. I need to use some supplements, but I got in the habit when we were still spending a lot of time Underground getting everything ready. No one built bathrooms down there and it was bad enough having to find places to pee!»

Toriel smiled as the kids descended into fits of laughter as Frisk described some of the weird things they’d had to do that first year. It wouldn’t be easy, but she was certain that Elliot would adjust just fine.


End file.
